A known electric compressor in the related art is provided with a compressing unit that compresses fluid and a motor unit that drives the compressing unit. The motor unit is provided with a rotor and a stator that generate a rotating force to be transferred to the compressing unit. The rotor is connected to the compressing unit, and the stator is fixed to the motor case of the electric compressor.
Known methods for fixing the stator to the motor case are press fitting, shrink fitting, and welding. Among these fixing methods, shrink fitting is a method which allows easy insertion of the stator into the motor case by heating the motor case to thermally expand it and fixing the stator in the motor case more firmly due to shrinkage of the motor case when its temperature decreases.
For fixing by shrink fitting, the problems of deformation of the motor case and stator insertion failures have been noted. However, various technologies for solving such problems have been proposed (for example, refer to Patent Documents 1 and 2); therefore, shrink fitting is used to fix stators into motor cases.
Patent Document 1: Japanese Unexamined Patent Application, Publication No. Hei-9-287585.
Patent Document 2: Japanese Unexamined Patent Application, Publication No. 2004-332614.